Double-deck　viaducts　based　on　traditional　ductility　design　are　vulnerable　to　earthquake-induced　damage.　To　control　the　seismic　damage,　a　double-deck　bridge　is　developed　with　the　lower　floor　designed　as　a　rocking　structure.　To　investigate　the　dynamic　response　of　the　rocking　bridge,　an　analytical　model　of　rigid　bodies　is　derived　through　the　Lagrange　method　and　momentum　conservation　law.　The　seismic　response　analysis　and　parametric　analysis　adopted　structural　parameters　such　as　the　size　and　dimension　parameter　of　columns　are　performed　using　this　model.　The　overturning　resistance　of　the　rocking　double-deck　bridge　is　estimated　qualitatively　and　quantitatively　with　a　mathematical　model　of　Ricker　wavelets.　The　results　show　that　the　rocking　double-deck　bridge　with　dimension　in　practice　can　satisfy　the　seismic　design　demand　of　the　E2　earthquake　according　to　the　seismic　design　code　of　bridges　in　China.　However,　the　rocking　bridge　is　more　prone　to　overturn　under　near-fault　ground　motions　with　a　high　amplitude　velocity　pulse.　The　overturning　acceleration　spectra　and　overturning　modes　of　a　rocking　double-deck　bridge　system　were　obtained　due　to　Ricker　wavelets.　The　rocking　bridge　is　more　stable　with　the　larger　slenderness　and　size　of　columns.　Copyright　©2020　Engineering　Mechanics.　All　rights　reserved.